And your guess is completely ignorant. It isn't racial and your "guess" is offensive. I have been on a jury panel in another city where a white guy who was up on charges of capital murder, (multiple counts), also had his cuffs removed before the potential jurors had the chance to see him. In his 3-piece suit and fresh haircut, he looked "safer" than most of the lawyers around the table. As a member of the jury panel. I couldn't tell who was the accused and who were the lawyers until they made him stand up.
In that city there were two deputies built like NFL linemen close by at all times, but it is standard procedure in all jurisdictions not to allow jurors to see an accused in cuffs, and IMHO, it's a good rule. Exceptions can and have been made if the guy has made verbal threats or tried something in court when not cuffed.